Example 19-1 Declaring an Input Value To Be JSON

This example specifies FORMAT JSON for SQL string values 'true' and 'false', in order that the JSON Boolean values true and false are used.

SELECT json_object('name'          VALUE first_name || ' ' || last_name,
                   'hasCommission' VALUE
                     CASE WHEN commission_pct IS NULL THEN 'false' ELSE 'true'
                     END FORMAT JSON)
  FROM employees WHERE first_name LIKE 'W%';

JSON_OBJECT('NAME'ISFIRST_NAME||''||LAST_NAME,'
-----------------------------------------------
{"name":"William Gietz","hasCommission":false}
{"name":"William Smith","hasCommission":true}
{"name":"Winston Taylor","hasCommission":false}

Example 19-2 Using JSON_OBJECT to Construct JSON Objects

This example constructs a JSON object for each employee of table hr.employees (from standard database schema HR) whose salary is less than 15000. The object includes, as the value of its field contactInfo, an object with fields mail and phone.

Because the return value of json_object is JSON data, FORMAT JSON is deduced for the input format of field contactInfo — the explicit FORMAT JSON here is not needed.

SELECT json_object('id'          VALUE employee_id,
                   'name'        VALUE first_name || ' ' || last_name,
                   'hireDate'    VALUE hire_date,
                   'pay'         VALUE salary,
                   'contactInfo' VALUE json_object('mail'  VALUE email,
                                                   'phone' VALUE phone_number)
                                       FORMAT JSON) 
  FROM employees
  WHERE salary > 15000;

-- The query returns rows such as this (pretty-printed here for clarity):

{"id":101,
 "name":"Neena Kochhar",
 "hireDate":"21-SEP-05",
 "pay":17000,
 "contactInfo":{"mail":"NKOCHHAR",
                "phone":"515.123.4568"}}

Example 19-3 Using JSON_OBJECT With ABSENT ON NULL

This example queries table hr.locations from standard database schema HR to create JSON objects with fields city and province.

The default NULL-handling behavior for json_object is NULL ON NULL.

In order to prevent the creation of a field with a null JSON value, the example uses ABSENT ON NULL. The NULL SQL value for column state_province when column city has value 'Singapore' means that no province field is created for that location.

SELECT JSON_OBJECT('city'     VALUE city,
                   'province' VALUE state_province ABSENT ON NULL) 
  FROM locations
  WHERE city LIKE 'S%';

JSON_OBJECT('CITY'ISCITY,'PROVINCE'ISSTATE_PROVINCEABSENTONNULL)
----------------------------------------------------------------
{"city":"Southlake","province":"Texas"}
{"city":"South San Francisco","province":"California"}
{"city":"South Brunswick","province":"New Jersey"}
{"city":"Seattle","province":"Washington"}
{"city":"Sydney","province":"New South Wales"}
{"city":"Singapore"}
{"city":"Stretford","province":"Manchester"}
{"city":"Sao Paulo","province":"Sao Paulo"}

Example 19-4 Using JSON_ARRAY to Construct a JSON Array

This example constructs a JSON object for each job in database table hr.jobs (from standard database schema HR). The fields of the objects are the job title and salary range. The salary range (field salaryRange) is an array of two numeric values, the minimum and maximum salaries for the job. These values are taken from SQL columns min_salary and max_salary.

SELECT json_object('title'       VALUE job_title, 
                   'salaryRange' VALUE json_array(min_salary, max_salary))
  FROM jobs;

JSON_OBJECT('TITLE'ISJOB_TITLE,'SALARYRANGE'ISJSON_ARRAY(MIN_SALARY,MAX_SALARY))
--------------------------------------------------------------------------------
{"title":"President","salaryRange":[20080,40000]}
{"title":"Administration Vice President","salaryRange":[15000,30000]}
{"title":"Administration Assistant","salaryRange":[3000,6000]}
{"title":"Finance Manager","salaryRange":[8200,16000]}
{"title":"Accountant","salaryRange":[4200,9000]}
{"title":"Accounting Manager","salaryRange":[8200,16000]}
{"title":"Public Accountant","salaryRange":[4200,9000]}
{"title":"Sales Manager","salaryRange":[10000,20080]}
{"title":"Sales Representative","salaryRange":[6000,12008]}
{"title":"Purchasing Manager","salaryRange":[8000,15000]}
{"title":"Purchasing Clerk","salaryRange":[2500,5500]}
{"title":"Stock Manager","salaryRange":[5500,8500]}
{"title":"Stock Clerk","salaryRange":[2008,5000]}
{"title":"Shipping Clerk","salaryRange":[2500,5500]}
{"title":"Programmer","salaryRange":[4000,10000]}
{"title":"Marketing Manager","salaryRange":[9000,15000]}
{"title":"Marketing Representative","salaryRange":[4000,9000]}
{"title":"Human Resources Representative","salaryRange":[4000,9000]}
{"title":"Public Relations Representative","salaryRange":[4500,10500]}

Example 19-5 Using JSON_OBJECTAGG to Construct a JSON Object

This example constructs a single JSON object from table hr.departments (from standard database schema HR) using field names taken from column department_name and field values taken from column department_id.

SELECT json_objectagg(department_name VALUE department_id) FROM departments;

-- The returned object is pretty-printed here for clarity.
-- The order of the object members is arbitrary.

JSON_OBJECTAGG(DEPARTMENT_NAMEISDEPARTMENT_ID)
----------------------------------------------
{"Administration":        10,
 "Marketing":             20,
 "Purchasing":            30,
 "Human Resources":       40,
 "Shipping":              50,
 "IT":                    60,
 "Public Relations":      70,
 "Sales":                 80,
 "Executive":             90,
 "Finance":              100,
 "Accounting":           110,
 "Treasury":             120,
 "Corporate Tax":        130,
 "Control And Credit":   140,
 "Shareholder Services": 150,
 "Benefits":             160,
 "Manufacturing":        170,
 "Construction":         180,
 "Contracting":          190,
 "Operations":           200,
 "IT Support":           210,
 "NOC":                  220,
 "IT Helpdesk":          230,
 "Government Sales":     240,
 "Retail Sales":         250,
 "Recruiting":           260,
 "Payroll":              270}

Example 19-6 Using JSON_ARRAYAGG to Construct a JSON Array

This example constructs a JSON object for each employee of table hr.employees (from standard database schema HR) who is a manager in charge of at least six employees. The objects have fields for the manager id number, manager name, number of employees reporting to the manager, and id numbers of those employees.

The order of the employee id numbers in the array is determined by the ORDER BY clause for json_arrayagg. The default direction for ORDER BY is ASC (ascending). The array elements, which are numeric, are in ascending numerical order.

SELECT json_object('id'         VALUE mgr.employee_id, 
                   'manager'    VALUE (mgr.first_name || ' '|| mgr.last_name),
                   'numReports' VALUE count(rpt.employee_id),
                   'reports'    VALUE json_arrayagg(rpt.employee_id
                                                    ORDER BY rpt.employee_id))
  FROM  employees mgr, employees rpt
  WHERE mgr.employee_id = rpt.manager_id
  GROUP BY mgr.employee_id, mgr.last_name, mgr.first_name
  HAVING count(rpt.employee_id) > 6;

-- The returned object is pretty-printed here for clarity.

JSON_OBJECT('ID'ISMGR.EMPLOYEE_ID,'MANAGER'VALUE(MGR.FIRST_NAME||''||MGR.LAST_NAME)
--------------------------------------------------------------------------------
{"id":         100,
 "manager":    "Steven King",
 "numReports": 14,
 "reports":    [101,102,114,120,121,122,123,124,145,146,147,148,149,201]}

{"id":         120,
 "manager":    "Matthew Weiss",
 "numReports": 8,
 "reports":    [125,126,127,128,180,181,182,183]}

{"id":         121,
 "manager":    "Adam Fripp",
 "numReports": 8,
 "reports":    [129,130,131,132,184,185,186,187]}

{"id":         122,
 "manager":    "Payam Kaufling",
 "numReports": 8,
 "reports":    [133,134,135,136,188,189,190,191]}

{"id":         123,
 "manager":    "Shanta Vollman",
 "numReports": 8,
 "reports":    [137,138,139,140,192,193,194,195]}

{"id":         124,
 "manager":    "Kevin Mourgos",
 "numReports": 8,
 "reports":    [141,142,143,144,196,197,198,199]}